SB20260731170 - Multiple vulnerabilities in TeamCity

Description

This security bulletin contains information about 2 vulnerabilities.

1) Deserialization of Untrusted Data (CVE-ID: CVE-2026-63077) Exploited

CWE-ID: CWE-502 - Deserialization of Untrusted Data

CVSSv4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to deserialization of untrusted data in the agent polling protocol when processing agent polling requests. A remote attacker can send specially crafted protocol data to execute arbitrary code.

2) Incomplete List of Disallowed Inputs (CVE-ID: CVE-2026-106218)

CWE-ID: CWE-184 - Incomplete List of Disallowed Inputs

CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to execute arbitrary code on the server.

The vulnerability exists due to incomplete filtering of dangerous inputs in the Kotlin DSL sandbox when executing Kotlin DSL code. A local user can escape the sandbox to execute arbitrary code on the server.

Remediation

Install update from vendor's website.

References

• https://www.jetbrains.com/privacy-security/issues-fixed/#a983751f1526a06f4037199996abfde1
• https://blog.jetbrains.com/teamcity/2026/08/cve-2026-63077-update/
• https://www.jetbrains.com/privacy-security/issues-fixed/#77bd8f90602eb633be2d9e6e3fa4a60f